Instructional theory is intended to guide instructional designers in selecting the best instructional methods for a given situation. There have been numerous qualitative investigations into how instructional designers make decisions and the alignment of those decisions with theoretical influences. The purpose of this research is to more quantitatively explore the question of how instructional designers actually use "instructional planning theory" to judge the usefulness of instructional methods. We asked 56 instructional designers to rate the usefulness of 31 instructional methods for six different cognitive domain content level conditions. The results show that content level has a statistically-significant influence on a designer's judgments regarding the usefulness of an instructional method. A designer's gender also has a statistically-significant influence on a designer's judgments regarding methods, but a weak effect size limits this result. Overall, the results provide evidence that supports the core principles of instructional planning theory, specifically method generality. The results also provide instructional designers further guidance in selecting the most useful instructional methods for cognitive domain content levels.